Tackling Terrible Traffic: How Cities Try To Ease Commutes

This is TALK OF THE NATION. I'm Neal Conan in Washington. Some of you are sitting in traffic right now, muttering darkly about how it's possible to hit every single red light. Los Angeles, a city that suffers more congestion than most, tried to unclog traffic for years by synchronizing its lights. Earlier this year, it became the first major city to tie all its traffic lights to a computerized system that uses motion sensors and cameras to monitor flows of traffic. They report modest improvements, but do drivers notice any change?

Cities across the country have tried countless ways to reduce congestion. So what are they doing in your town to reduce traffic? Give us a call, 800-989-8255. Email us, talk@npr.org. You can also join the conversation on our website. That's at npr.org. Click on TALK OF THE NATION.

Later in the program, we'll talk to our favorite film buff Murray Horwitz about the best prequels ever. You can email us your nominees right now. The address again is talk@npr.org.

But first reruns: Sitting in traffic in L.A. We begin with KTLA's traffic anchor Ginger Chan. She joins us by phone from her home in Los Angeles. Good of you to be with us today.

GINGER CHAN: Yeah, thank you so much, Neal. I listen to your many times folding laundry and cooking meals. So it's very, very much an honor to be here with you.

(LAUGHTER)

CONAN: Well, thanks very much. Have you noticed any changes since a couple of months ago when this new computerized system went into effect?

CHAN: Well, it's funny because you were talking about how long it's been. It's actually been about 30 years since they've been working on this synchronization process. And I think that it's a slow but sure process. I mean, they're saying that - experts are saying that they're saving when you drive about a five-mile distance from 20 minutes to 17.2, you travel 10 miles obviously you're saving about six minutes.

So it is hard to notice that change I think initially. When you're sitting at a red light, you just feel like it's there forever, especially since if you drive the same route, you usually know when you're sitting at an intersection, you know you're at Sunset Boulevard perhaps, you know how long it's going to take. All of a sudden, it's taking that much longer.

But I think it's something that in the long term, a couple years from now, people will actually start to feel the impact because the city has to make changes. And as you know, you know, it's such an impacted city that these are just some of the things that they're doing that are going to work, but it's going to take a little time for people to get used to it.

CONAN: And I have to ask, there any number of jurisdictions in what we think of Greater Los Angeles. In Burbank, for example, is their system tied into the L.A. system?

CHAN: No, I think a lot of those other systems, a lot of other cities like Burbank or Glendale, they're going to try to do it, but right now it's just the major city of L.A. But we're also talking about 4,500 traffic signals over 469 miles of the city of Los Angeles. So that's a lot of signals.

CONAN: Has anybody tried it, to drive all the way from Pasadena down to the ocean without catching a red light?

CHAN: I think somebody has tried it. I don't think they were successful, actually.

(LAUGHTER)

CHAN: I've heard of some reporters, some paper reporters who have tried it. But yeah, they were not successful at doing it at all.

CONAN: And this is hardly the first or only attempt. As you suggest, they've been trying this for decades, really, in incremental steps. And obviously we're talking about the streets. The freeways are also a problem.

CHAN: I think that's the challenge now because Los Angeles has so many people who are taking the streets instead of taking the freeways because, you know, the freeways are so impacted that now they have to do something to kind of fix the streets. The other problem is you have major streets where we have the synchronization, but then you have all these smaller streets that if people know about people use that don't have the synchronization system. So there is still that challenge that people face when they're maneuvering through the city. And it's cost them over $400 million over that 30-year period.

CONAN: That's no small fee. But there was, I do remember, what, last year, Carmageddon as they were trying to expand the freeway system.

CHAN: The dreaded Carmageddon.

(LAUGHTER)

CHAN: They're trying to expand it, but they're also trying to improve it. And I will say some of those improvements also means - and I say improvements in air-quotes - some of those mean turning free carpool lanes into fast-track toll lanes now. So those are some of the different things they're trying to improve the flow of traffic. But it is such a challenge.

And remember, you know, being here in L.A., we have a lot of other things. I mean, you have, being in D.C., obviously the president making his travels around town all the time. But when we have it here, it's very different than in, say, Henderson, Nevada. We have the Oscars. We have a Hollywood marathon on Saturday. We have the L.A. marathon.

You know, we have a lot of sporting events. All of those things are part of the reason, I think, that contributes to them really pushing for this traffic synchronization.

CONAN: Possibly two of the few cities in which the motorcade is a form of mass transit.

CHAN: That's true, that's true. It's pretty much necessary for a helicopter, or in my case like a broom, something like that, though.

(LAUGHTER)

CONAN: I wonder, when they talk about improvements, does anybody ever ask you?

CHAN: They don't. If they did, I don't think they would necessarily agree with some of the things I would suggest. My thinking, and there is actually a congressman who wants this to be done on the 134 freeway, which runs through Burbank, is making the carpool lane, well, free for sure, but in addition to that, in off-peak hours and sometimes in peak hours, just let people who are not carpooling drive in it.

No one has asked me that. I think it's a great idea because, like I said, anything that would make that flow of traffic more efficient.

CONAN: And how bad does it get?

CHAN: Well, I've seen it where they talk about sensors on the freeways and the streets that will tell you, you know, how fast you're moving, say 10 miles per hour. I've seen when it's at zero. I've seen it when the lights cycle green, you think that it's moving, and actually you're sitting so long on a traffic sensor on the ground that it cycles to thinking that you're not even on the road because you've been sitting there for so long. Does that make sense?

CONAN: You couldn't possibly be there anymore.

CHAN: Yeah, it's like you're not even there, but yet you've been there for literally over an hour. And really to speak of two, two days ago, there was a police pursuit, and the suspect took off on foot. They had to shut down a major freeway, the 10 freeway right at Crenshaw and Adams. Surface streets were all congested. This is during major traffic time in the afternoon. I mean, you can only imagine this is the other challenge that we face.

And that synchronization I will say has helped to some degree because the central command center, where they look at all of the intersections that are tied up with traffic, they are able to help move that flow of traffic by kind of playing God, I would say, and, you know, hitting that green light and keeping it there longer so people can move.

CONAN: Well Ginger Chan, thank you very much for your time today, and we appreciate the kind words.

CHAN: Truly an honor.

CONAN: Ginger Chan, traffic anchor at "KTLA Morning News" in Los Angeles, joined us by phone from her home in that city. And we want to hear from you. What is your town or city doing to improve traffic congestion? 800-989-8255. Email us, talk@npr.org. Tom Vanderbilt is the author of "Traffic: Why We Drive the Way We Do (and What It Says About Us)." He joins us now by smartphone from his home in Brooklyn, a place that's also seen some traffic from time to time. Good to have you with us.

TOM VANDERBILT: Great to be here, Neal, thank you.

CONAN: And I wonder: Do you think this is a valid approach in Los Angeles?

VANDERBILT: Yeah, certainly. And as Ginger said, they've been working on this for a while and just getting closer to that 100-percent point, which they've actually reached. But, you know, you certainly want more intelligence on the roads. And, you know, in a city like Los Angeles or any major city at this point in time, we're not adding new roadway. That's not the way to combat congestion.

So so-called ITS, that's intelligence transportation systems, using computers to sort of winnow out these inefficiencies where you can, and, you know, it might only be five- or 10-percent improvement, but in some ways, you know, that's all you need. And in some - you know, traffic's a non-linear phenomenon, which is a short way of saying, you know, five-percent improvement can be a 15-percent improvement in speed. So, you know, I'm all for ATSAC.

I wish we had 100 percent of our lights in New York. We're getting there but not yet.

CONAN: Not yet, and so this is coming on-stream in bigger cities across the country?

VANDERBILT: Yeah, I mean, it's very expensive. I mean, I was looking at something from New York. There was a study done on Staten Island, you know, one of our boroughs, of course, just to study the possibility of putting in a sort of synchronized green-wave system on one of the arterial roads is $1,000 per intersection just to do the study much less, you know, then put in the computer, fiber-optic hardware.

So L.A. got a big boost when it had the Olympics, which is partially why it installed the ATSAC system. You know, not every city has that sort of money. So most places in America, you know, we're still using these sort of timing systems, preset timing systems, traffic lights. And they might change depending on morning peak, evening peak but, you know, far from the intelligent system that Los Angeles has.

CONAN: So they're sequenced lights on the theory that if you're doing more or less the speed limit, say 35 miles an hour, you'll catch all the green lights. And of course that may have happened once, probably in 1956.

VANDERBILT: Exactly. And, you know, there's also any number of things that can go wrong, I mean a stalled vehicle. There might be too many - there might be more cars than usual trying to make a left turn, I mean, and don't even talk about left turns in Los Angeles. But traffic is very predictable on the one hand, but it also can go very wrong.

An important part of the ATSAC system in Los Angeles is that there are a lot of cameras at intersections, too, which enables engineers if something does show up to be going wrong, they can actually look at it and assess the situation and then make a move from there, just again having that global system of intelligence.

And I must add that it's a bit unnerving to be in the traffic bunker there on sort of a Sunday, not a peak period, and to realize that the system is actually pretty much running itself, kind of like, you know, Hal in "2001." It is a truly automated system. And, you know, an engineer will be phoned at home if something really goes wrong, but it does, you know, kind of run the city by itself.

CONAN: Isn't this the kind of system that in various movies, you think of "The Italian Job," thieves hack into in order to divert the money so that they can get away?

VANDERBILT: Exactly, and I don't know if that's actually occurred in real life. And, you know, it does bring up a point, which is sort of the flipside of this, which is at some point, you know, at some point the system has its limits. And as we sort of mentioned in the part you played at the beginning of the show, you know, if you have a grid system like Los Angeles, there's going to be a competing demand coming from another direction.

If you think - an analogy that was given to me was an elevator. And certainly you don't want an elevator stopping on an empty floor, at every empty floor when you're on it trying to get to the bottom. But, you know, should that elevator go straight from floor 100 to floor zero without stopping at all? What about all those people that you're sort of leaving on all those other floors?

And if you think about in Los Angeles, you know, if someone wants to cross a street on foot, if there's a couple cars coming from another direction, you know, at what point do you interrupt that nice green wave to let the other, you know, sort of - other stream of traffic through.

So, you know, traffic is this set of competing desires, and you can't just have these monolithic one-way flows, you know, straight from your place of work to your home for every commuter. So there is a balance that has to be set there.

CONAN: And competing interest might include a concert at one venue and a ballgame at another.

VANDERBILT: Yeah, I mean, there's any number of competing interests, competing modes, strange things that happen. So yeah, I mean, there's - and let's not forget things like buses or trains. That's another nice thing about L.A. is they can really fine-tune the traffic control system to help, for example, speed if a special bus service is running behind schedule. They can, you know, tinker with the lights in real time to make that bus go faster, to catch up to its route.

If the bus is running just on schedule, it will sit in traffic lights with all the other cars. And you can also avoid things like having trains, light-rail system be stuck in the middle of an intersection, which would cause all sorts of havoc, of course. So...

CONAN: We're talking with Tom Vanderbilt, author of "Traffic: Why We Drive the Way We Do (and What It Says About Us)." And we want to see what your town is doing to try to decongest traffic. Los Angeles, of course, is synchronizing its lights in a computerized system. What's your town doing? 800-989-8255. Email us, talk@npr.org. Stay with us. I'm Neal Conan. It's the TALK OF THE NATION from NPR News.

(SOUNDBITE OF MUSIC)

CONAN: This is TALK OF THE NATION from NPR News. I'm Neal Conan. In Los Angeles, slow and stopped traffic has long been the norm. The city has tried to fight it with subways and light rail, carpooling incentives, road improvements, all without too much effect. Now they're taking another tack to try to make life easier for the city's nearly seven million commuters: magnetic sensors in the roads at every intersection work with hundreds of cameras feeding a centralized computer system information to help it adjust the timing of 4,500 lights.

Not only that, it knows when buses are running behind. It picks up bicycle traffic. It even records pedestrians. The system is relatively new. So far the city reports some modest success in dropping drive times. What has your town tried to do to improve traffic congestion? 800-989-8255. Email us, talk@npr.org. You can find us on Twitter, @totn. Tom Vanderbilt, author of "Traffic: Why We Drive the Way We Do (and What It Says About Us)," is our guest. And let's see if we can go to Jesse(ph), Jesse on the line with us from Tulsa.

JESSE: Hi Neal. I was just going to say that in downtown Tulsa, if you drive 17 between all the stoplights, you'll hit every green one.

CONAN: Every single time?

JESSE: Yeah, and first I thought it was a coincidence. My friend told me. But it works, and every time I'm with someone, I tell them. And they're always skeptical at first.

CONAN: And does this include rush hour, any time of the day?

JESSE: As far as I know it's any time of the day. It's worked every time I've tried it.

CONAN: And tell us about traffic in Tulsa. You don't think of it as one of the major traffic congestion sites in the country.

JESSE: Oh yeah, it's definitely not, I'm sure.

CONAN: I'm sure, OK. Well thanks very much. So that's, Tom Vanderbilt, one example of synchronized lights, the timing system.

VANDERBILT: Yeah, exactly, and in New York City, it's - I've been told by engineers it's about generally 27 miles an hour on a number of the city's streets. And I drive that myself. And you notice with some amusement and frustration that taxi drivers are kind of the biggest violators of this, you know, just want to accelerate as quickly as they can toward that red light, not - instead of maintaining that even, slow, steady speed.

But (unintelligible) there is a wonderful system in Europe which utilizes speed cameras, and it actually detects if you're going above the speed limit, and if it does, it will change the light to red. And if you're going the speed limit or below, it will keep the light green for approaching traffic. So just another sort of a way to game the system.

CONAN: Here's an email from Ross(ph) in Anchorage: While there are not many traffic problems in cities up here, slow-moving RVs on the long-stretch highways can cause delays over an hour and major accidents. Now when you're driving these highways, you'll see signs that say delay of more than five vehicles is illegal; use pull-outs to let faster traffic pass.

And I guess that's a way to accommodate people who are stuck behind those RVs that, yes, can wallow along the road.

VANDERBILT: Competing desires, that's all I can say.

CONAN: Let's see if we can go to another call. This is Andrew(ph), Andrew with us from Schofield Barracks in Hawaii.

ANDREW: Yes, hello, how are you doing?

CONAN: Very well, thanks.

ANDREW: The issue with our town was mainly we had a road open, and Hawaii is ridiculous with traffic just because everybody travels at the same time. Military, everybody's on the roads, you know, early to get to work by 6:30. Well, what our town did was they built...

CONAN: I'm sorry - Andrew, I'm sorry, your town did was build...

ANDREW: We built a - they built a road that cut 30 minutes off the trip for just military. And by doing that, they eliminated tens of thousands of cars that were on the interstates. So...

CONAN: I'm sure. Did they in the process anger everybody who did not have a military license plate?

ANDREW: Yes, they did, but at the same time they also made them a bit happier because all the congestion on the interstate, they didn't have to worry about that because they eliminated I think they said somewhere around 50,000 or 70,000 cars on the interstates alone. But the problem was is they had it the wrong time. So what they did was they went, and they asked military and people in general what times they were traveling and what times the congestions were bad. And they changed so that the road was open at the specific time that everybody was traveling.

And so they fixed the issue with the congestion by just making a dedicated road for high, you know, military, this is mainly military installations and stuff. Because there were so many people that were driving in the morning, they were congesting all the roads for the regular, you know, public people that were driving back and forth to work.

CONAN: Yeah, we call those civilians.

ANDREW: Yes, I've heard of them before. I have never met one myself.

(LAUGHTER)

ANDREW: But I thought that that also might work for areas that - as long as they talk to the actual person and find out what times, you know, the congestions are worse, maybe they can eliminate some of the cars and the vehicles, I believe, on the roads at certain times if they - let's say instead of working to a nine to a five, a business could be open from eight to four, and then another business could be open at a different time.

I just - I assume that might work, that might help out by eliminating cars on the road all at the same time that they would eliminate congestion. That's just my...

CONAN: Tom Vanderbilt, is this an approach that might work elsewhere?

VANDERBILT: Well, you know, as I said, in a major city like New York, I can't see, you know, where we're going to get, you know, the sort of empty road space. But the caller does make a valid point, which is that, you know, the time element, it's not just space, it's time. When are people on these roads?

And this is something that Los Angeles was trying to deal with as early as the 1920s, to get people to stagger their work times. And, you know, unfortunately, this is just the way sort of, you know, modern or just civilization works. We all need to sort of be at the same place at the same time to exchange, you know, ideas and information and be productive citizens.

So it's - which is not to say that in the last Olympics in London, for example, they did all sorts of interesting experiments to make the congestion lower there, including businesses started scheduling deliveries at night, kind of using more innovative, you know, just in time deliveries rather than having trucks on the road with the Olympic athletes, who actually did get their own special lane, as well, their own traffic lane, as well.

So it does happen but only in, you know, sort of in extreme situations. It's not really going to work in a normal city.

CONAN: Andrew, thanks very much.

ANDREW: Thank you.

CONAN: Here's an email that we have from Victoria(ph) in Rochester, New York: You said there were no streetlights coordinated since the 1950s, so you don't have to stop if you go at the speed limit. Au contraire. I lived in Philadelphia in the '80s. Chestnut Street, a one-way street, was perfectly coordinated. You could turn onto it where it began at Cob Creek Parkway and ride it all the way downtown if you followed the speed limit. I don't know if that's still true, but it was great.

And this from Lauren Alexander(ph) in Kansas City. The city recently disabled many of the stoplights in exchange for blinking traffic lights. At first the congestion was terrible, as if drivers forgot what the blinking red and yellow lights signified. It's been a few months now, and traffic is notably improved in my perspective.

So in other words, blinking red would be stop still, I think, Tom Vanderbilt, and blinking yellow would still be caution.

VANDERBILT: Yeah, which I haven't seen that particular configuration myself, but it raises, you know, the question of other ideas, such as roundabouts, which, you know, do you actually need traffic lights at all, rather than having this on-off situation. Can you have a roundabout in which people are always essentially moving through the intersection, perhaps more slowly than with a green light, but again there's no sort of on, off, people aren't waiting, it's more of a fluid situation.

But gain, there's no silver bullet in traffic engineering. You have to look at each situation, each set of circumstances. Every road is sort of different. Every traffic scenario is different. So interesting idea, though.

CONAN: Let's go next to Zack(ph), and Zack's with us from Union, Missouri.

ZACK: Hey Neal, thanks for taking my call.

CONAN: Sure.

ZACK: I'd just like to say first that we're really going to miss you in June. I love your show, listen to it every day.

CONAN: Well, thanks very much for that.

ZACK: Yeah, in our town, the past couple years they've been putting in roundabouts, and I love them a lot. Like he just said, it keeps the traffic going. You're not sitting there. We have a lot of industrial traffic where I live, a lot of big trucks and stuff. So that can really put a, you know, logjam into the system.

And then we're kind of outside St. Louis, Missouri, and they have advisory speeds that they posted on one of the major highways, which might work out great, but nobody ever follows it.

(LAUGHTER)

ZACK: So can't really say there.

CONAN: How was adjustment to the roundabouts? Some people find it difficult to adapt to, at least at first.

ZACK: Not really for me. I mean, I don't know, I'm pretty young, I'm about 30 years old and stuff. It seemed like for the older folks it might have been a little weird, but I don't want to stereotype, but that just seemed to be my perception, so...

CONAN: All right, well, thanks very much, Zack.

ZACK: All right, thanks.

CONAN: Is there an adaptation period to things like roundabouts, Tom Vanderbilt?

VANDERBILT: Oh absolutely, and unfortunately a lot of the news coverage right when they've first gone in, so all the news is negative. And if you check back in a few years later, people would sort of say oh yeah, the roundabout, no big deal. But I should caution, you know, in a city like Los Angeles, again when the traffic lines are at a certain level, you know, roundabouts do become less - those sorts of situations becomes less tenable, and you do have to just have brute force allotment of right of way with traffic lights, but absolutely adaptation period.

CONAN: Here's a tweet from RezzaUp(ph): Roundabouts are big here in the north suburbs of Indianapolis. I think they're great.

And Janice 303(ph) sent a tweet about Denver's light rail transit system. He says: It's proved to reduce car congestion. One reason is it parallels our major highways. You can't drive on a highway without seeing the light rail pass you.

VANDERBILT: Yeah. I mean, the psychological impact of that must be enormous. And I should, you know, mention this is, even talking about Los Angeles, this is more than just engineering. There's a certain amount of psychology that must be considered here, and this comes into play with waiting at red lights.

And the idea - I mean, part of the frustration with people like myself is when you go to a red light, and, of course, there isn't going to be anyone else waiting, and you're sort of - from the world of queue psychology, there's - one of the rules is that unexplained waits feel longer than explained waits.

So there's nothing more frustrating than just sort of sitting at a light that seems to have no reason for (technical difficulty) people through. It's just basically holding you up at two in the morning. And so, again, just an important thing to consider when we talk about traffic lights.

CONAN: Let's see if we can go to - this is Sam(ph). Sam's calling from Denver.

SAM: Yes. Hi, Neal. Good to be on.

CONAN: Thanks.

SAM: Yeah. Well, I live down in Denver, but what I wanted to comment on was, you know, one of our greatest pastimes here in Colorado is the ski and snowboard industry. And every weekend the highway gets absolutely cluttered going into the mountains.

And one way that we've actually figured to help keep the congestion down, or at least keep the traffic moving constantly, is they'll send out a squad car out in sections of maybe a mile-and-a-half or so, and they'll just keep the traffic going at a constant pace of about 20 miles an hour.

And they'll try to put these big gaps in between the traffic for about five or six miles, and then they'll go back, take an exit and then go back around and try to keep sectioning off the traffic.

CONAN: And sectioning off the traffic so it will keep moving.

SAM: Yes, exactly.

CONAN: I've never heard of that. Tom Vanderbilt, are you familiar with that?

VANDERBILT: Yeah, indeed. It's a great example, and I wrote a column about this for Slate magazine. And it's called - it's sort of called speed harmonization, and the idea is that - it's sort of a counterintuitive slower-is-faster effect. Often, what happens when you get vehicles moving at high speeds, if there's sort of a quick braking incident, you get the other vehicles behind it braking very quickly, and there's sort of a shock wave that is sent back that, through, you know, reasons of complicated physics, if you could sort of damp out that wave and not have people drive into that stop-and-go traffic, it will actually be much more efficient over the length of the highway.

And you actually get - you can get higher, you know, what they call throughput on a highway facility by having people drive, say, 55 than 75, which, again, it goes against what people's idea of efficiency would be. Oh, we should just drive as quickly down that.

And you see that a lot - again, I mentioned ITS. This is - often you'll have, on the highways, signs telling you to drive a certain speed, and they've put that speed up there, and it's dynamic and flexible. They put that speed up there. They judge it to be the best speed for the current condition. You see it a lot more in Europe than here, but it's coming to places like Virginia.

CONAN: Well, Sam, thanks very much. Interesting.

SAM: Thank you.

CONAN: We're talking about traffic. You're listening to TALK OF THE NATION from NPR News. And let me reintroduce Tom Vanderbilt, author of "Traffic: Why We Drive the Way We Do (and What That Says About Us)."

And let's see if we can get another caller in and go to Joe(ph). Joe's with us from Tulsa.

JOE: Hi, Neal. I wanted to tell you about an experience I had in Kansas City, Missouri. I was at a left turn light, and it had a sensor on it. I found that if a car was not on the sensor, that part of the cycle would be completely skipped so that the other traffic could keep going. And I was stuck behind somebody who apparently didn't realize that and was just off the sensor because the sensor was too small or too close to the line or something.

And I was stuck honking and waving at this person, trying to get them to pull forward just a little bit for five or six minutes, with a screaming baby in my backseat. So, you know, they were trying to keep the traffic going and make it so that an unnecessary left turn light would never come on if there was nobody there, but it didn't quite work right.

CONAN: It's a - sometimes these technological fixes, Tom Vanderbilt, are so delicate that they're counterproductive.

VANDERBILT: Yeah. Those are basically sort of big metal detectors, and they don't - you know, it's been pointed out that they don't detect carbon fiber, you know, bicycles. So if you have a fancy carbon fiber bike, you may sit at an intersection and, I think, as Ginger mentioned, almost at an existential dilemma: You're there, but you're not there at the same time, or no one knows you're there.

But, yeah. Again, there's always unintended consequences with any new technology, and I'm sure they've worked on getting the sensors to be more - have more accurate readouts or not leave phantom vehicles stranded at the intersection.

CONAN: Joe, thanks very much for the call.

JOE: Thanks.

CONAN: And, Tom Vanderbilt, as you think about the future of this, we say more and more cities are using this integrated traffic system, or intelligent traffic system, and other things are coming online. Are we going to approach the day when we have those driverless cars all going the same speed at the same time and this is going to be a panacea?

VANDERBILT: It would certainly help with all sorts of things: safety and traffic flow. I mean, I don't think - panacea is too strong a word. I mean, there's - even improving the roads in LA brings its own sort of hidden risk, which is that Anthony Downs, a researcher, has called it the triple convergence problem, which is that if you make a road faster, you have the potential to bring people - take people off of other modes of transport, take them from other roads or take them from other times of day onto that newly, you know, sort of desirable road.

So traffic is such a dynamic system that you can have a sort of induced demand where you make something faster, it becomes more attractive and it just sort of fills back up. So we may have just hit a limit here but for the time being, this system is certainly better than, you know what came before. Well, it does raise the question of I'm not sure how people are going to check their email while driving in Los Angeles if they're no longer waiting at red lights. This could be, you know, its own social problem we haven't figured out yet.

CONAN: Tom Vanderbilt, thanks very much for being with us today. We appreciate your time.

VANDERBILT: Thank you.

CONAN: Tom Vanderbilt, the author of "Traffic: Why We Drive the Way We Do (and What It Says About Us)." A quick update on a story you heard in the last newscast about that lost hiker in California. Orange County Sheriff Lieutenant Jason Park confirms Kyndall Jackson(ph) has been rescued and now is in a hospital. She's appeared disoriented and dehydrated but responsive to rescuers. Her fellow hiker was rescued last night. He remains in serious condition. Years before his infamous run-ins with Shrek, Puss in Boots settled some scores and cleared his name from a bank robbery he was tricked into committing with his childhood friend who you may know from nursery rhymes.